/**************************************************************************
 *
 * Copyright 2013-2014 RAD Game Tools and Valve Software
 * Copyright 2010-2014 Rich Geldreich and Tenacious Software LLC
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 **************************************************************************/

#ifndef D_FILE_OFFSET_BITS
#define _FILE_OFFSET_BITS 64
#endif
#ifndef _LARGEFILE64_SOURCE
#define _LARGEFILE64_SOURCE 1
#endif

#include <sys/types.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <limits.h>
#include <stdlib.h>

#include "regex.h"

#include "utils.h"
#include "regerror.ih"

/*
 = #define	REG_OKAY	 0
 = #define	REG_NOMATCH	 1
 = #define	REG_BADPAT	 2
 = #define	REG_ECOLLATE	 3
 = #define	REG_ECTYPE	 4
 = #define	REG_EESCAPE	 5
 = #define	REG_ESUBREG	 6
 = #define	REG_EBRACK	 7
 = #define	REG_EPAREN	 8
 = #define	REG_EBRACE	 9
 = #define	REG_BADBR	10
 = #define	REG_ERANGE	11
 = #define	REG_ESPACE	12
 = #define	REG_BADRPT	13
 = #define	REG_EMPTY	14
 = #define	REG_ASSERT	15
 = #define	REG_INVARG	16
 = #define	REG_ATOI	255	// convert name to number (!)
 = #define	REG_ITOA	0400	// convert number to name (!)
 */
static struct rerr
{
    int code;
    char *name;
    char *explain;
} vogl_rerrs[] =
      {
          { REG_OKAY, "REG_OKAY", "no errors detected" },
          { REG_NOMATCH, "REG_NOMATCH", "regexec() failed to match" },
          { REG_BADPAT, "REG_BADPAT", "invalid regular expression" },
          { REG_ECOLLATE, "REG_ECOLLATE", "invalid collating element" },
          { REG_ECTYPE, "REG_ECTYPE", "invalid character class" },
          { REG_EESCAPE, "REG_EESCAPE", "trailing backslash (\\)" },
          { REG_ESUBREG, "REG_ESUBREG", "invalid backreference number" },
          { REG_EBRACK, "REG_EBRACK", "brackets ([ ]) not balanced" },
          { REG_EPAREN, "REG_EPAREN", "parentheses not balanced" },
          { REG_EBRACE, "REG_EBRACE", "braces not balanced" },
          { REG_BADBR, "REG_BADBR", "invalid repetition count(s)" },
          { REG_ERANGE, "REG_ERANGE", "invalid character range" },
          { REG_ESPACE, "REG_ESPACE", "out of memory" },
          { REG_BADRPT, "REG_BADRPT", "repetition-operator operand invalid" },
          { REG_EMPTY, "REG_EMPTY", "empty (sub)expression" },
          { REG_ASSERT, "REG_ASSERT", "\"can't happen\" -- you found a bug" },
          { REG_INVARG, "REG_INVARG", "invalid argument to regex routine" },
          { -1, "", "*** unknown regexp error code ***" },
      };

/*
 - regerror - the interface to error numbers
 = extern size_t regerror(int, const regex_t *, char *, size_t);
 */
/* ARGSUSED */
size_t
vogl_regerror(errcode, preg, errbuf, errbuf_size) int errcode;
const regex_t *preg;
char *errbuf;
size_t errbuf_size;
{
    register struct rerr *r;
    register size_t len;
    register int target = errcode & ~REG_ITOA;
    register char *s;
    char convbuf[50];

    if (errcode == REG_ATOI)
        s = vogl_regatoi(preg, convbuf);
    else
    {
        for (r = vogl_rerrs; r->code >= 0; r++)
            if (r->code == target)
                break;

        if (errcode & REG_ITOA)
        {
            if (r->code >= 0)
                (void)strcpy(convbuf, r->name);
            else
                sprintf(convbuf, "REG_0x%x", target);
            assert(strlen(convbuf) < sizeof(convbuf));
            s = convbuf;
        }
        else
            s = r->explain;
    }

    len = strlen(s) + 1;
    if (errbuf_size > 0)
    {
        if (errbuf_size > len)
            (void)strcpy(errbuf, s);
        else
        {
            (void)strncpy(errbuf, s, errbuf_size - 1);
            errbuf[errbuf_size - 1] = '\0';
        }
    }

    return (len);
}

/*
 - vogl_regatoi - internal routine to implement REG_ATOI
 == static char *vogl_regatoi(const regex_t *preg, char *localbuf);
 */
static char *
vogl_regatoi(preg, localbuf)
    const regex_t *preg;
char *localbuf;
{
    register struct rerr *r;

    for (r = vogl_rerrs; r->code >= 0; r++)
        if (strcmp(r->name, preg->re_endp) == 0)
            break;
    if (r->code < 0)
        return ("0");

    sprintf(localbuf, "%d", r->code);
    return (localbuf);
}
